Get Paid to Write at Home
Log Writer (LGWR) writes all the entries from the redo log buffer to the active online redo log group. If there are two or more files in the online redo log group (as there ideally should be), LGWR will write to all the members in that group simultaneously. If LGWR can write to only one member of the active redo log group, it will do so, but it will issue an error in the alert log. In the event that LGWR cannot write to any of the online redo log members, the database will require a more in-depth recovery, as detailed in Chapter 9. In that case, the DBA must exercise caution because it is easy to lose data accidentally in this scenario.
You can access Writer either through its shortcut on the panel or by going to the Applications, Office menu and selecting Word Processor. After a few seconds, Writer opens up with a blank document and a blinking cursor awaiting your command. It can be tempting to just dive in and start typing your document, but it can be worthwhile to do some initial configuration before you start work. Also shown in Figure 6.4 are a set of options that are specific to Writer. From top to bottom, they are . General Specify options that affect the general use of Writer. . View Specify what you want Writer to display. . Print Specify exactly what you want Writer to output when you print your document. . Table Set options for drawing tables within Writer. . Changes Define how Writer handles changes to documents. . Compatibility A set of rules that Writer uses to ensure close compatibility with earlier versions of Writer.
As I mention in the preceding paragraph, OpenOffice.org Writer is a word processing program. If you've ever used a word processing program before, you should be able to easily begin using OpenOffice.org Writer. To start the program, click the OpenOffice.org Writer icon from the desktop panel (it looks like a pen and two sheets of paper) or choose ApplicationsOOfficeO OpenOffice.org Writer. The first time you open the program, you're prompted to register the program and then you are presented with a blank document, as shown in Figure 3-8. I can't go into a detailed explanation about using OpenOffice.org Writer that could be a complete book in itself. However, I will show you how to open documents and save them in other formats. So instead of using MS Office to do your work, you can use OpenOffice.org instead and share your work with others still using MS Office. To open a document in OpenOffice.org Writer, do the following OpenOffice. org Writer program main window. OpenOffice. org...
Out of all the applications that make up OpenOffice.org, the one that you are most likely to use on a regular basis is Writer, the OpenOffice.org word processor. With a visual style similar to Microsoft Word, Writer has a number of strengths over its commercial and vastly more expensive rival. In this section, you learn how to get started with Writer and make use of some of its powerful formatting and layout tools. You can access Writer either through its shortcut on the panel or by going to the Applications, Office menu and selecting Word Processor. After a few seconds, Writer opens with a blank document and a blinking cursor awaiting your command. It can be tempting to just dive in and start typing your document, but it can be worthwhile doing some initial configuration before you get stuck in.
Before you begin using Writer, I want to give you a quick overview of its major features. When you know what you can do with Writer, you can read the subsequent sections to find out how to perform specific tasks in Writer, such as formatting tables, printing documents, and tracking changes. You can do the following with Writer Open and edit Microsoft Word files or convert Microsoft Word files to Writer format. One advantage of converting to Writer format is that Writer files are much smaller in size than corresponding Microsoft Word files. Create a mail merge where you write a single document with generic fields and have Writer automatically create many different customized documents by filling in the specific fields (such as name, address, and phone number) from a database. E-mail your documents directly from Writer. If you like, Writer can automatically complete the word you're typing by making a best guess and you can accept the choice by pressing Enter. (If this feature drives you...
To familiarize yourself with Writer, start by examining the user interface components packed into its main window, shown in Figure 1-2. As Figure 1-2 shows, you can view the Writer window in terms of the following major parts The Writer The Writer Menu bar Provides the standard pull-down menus File, Edit, Help, and so forth. Use these menus to perform all the tasks that Writer can do. In addition to these parts, the largest part of the Writer window is the work area where your document appears. That's where you focus most of your attention. Use tooltips to get a clue about what a particular field or button does. Mouse over a field or a button and Writer displays a small tooltip window with a brief help message. If you want more information in the tooltips, turn on extended tooltips by choosing HelpOExtended Tips. On the other hand, if you don't like these tooltips, toggle them off by choosing HelpOTips and HelpOExtended Tips. If you need it, help is available in Writer. Choose...
You'll have no problem preparing documents using Writer. Typically, you can simply click to position a cursor and then type your text. To format text, select a style for the paragraph or select text and then apply formatting, such as boldface or italics. In the following sections, I provide some quick tips on how to perform specific document-preparation tasks in Writer. I organize the tips into the following categories of tasks
One of the most surprising and welcome applications to see the light of day has to be OpenOffice Writer, one of a handful of applications that comes with the free, open source OpenOffice suite. This powerful word processor is providing some serious competition for the best-selling Microsoft Word. In this chapter, I introduce you to OpenOffice Writer, one of three OpenOffice apps covered in the book. (Chapter 6 will cover OpenOffice Calc, a spreadsheet app Chapter 7 will cover OpenOffice Impress, a slideshow presentation app.)
OpenOffice.org Writer (Applications Office OpenOffice.org Word Processor), shown in Figure 11-1, is the word processor component. As with Microsoft Word, it's fully WYSIWYG (What You See Is What You Get), so you can quickly format text and paragraphs. This means the program can be used for elementary desktop publishing, and pictures can be easily inserted (using the Insert menu). Figure 11-1. OpenOjfice.org Writer Figure 11-1. OpenOjfice.org Writer Writer's toolbars provide quick access to the formatting tools, as well as to other common functions. The vast majority of menu options match those found in Word. Right-clicking the text itself also offers quick access to text-formatting tools. As with all OpenOffice.org packages, Writer is fully compatible with Microsoft Office files, so you can save and open .doc files. Just click File Save As, and click the arrow alongside File Type to choose a document format. The only exception is password-protected Word files, which cannot be opened....
OpenOffice.org (www.openoffice.org) is a suite of office applications including a word processor (Writer), a spreadsheet (Calc), a drawing program (Draw), software for creating presentations (Impress), and a database program called Base, which keeps tagging along after the rest of OpenOffice. This section focuses on the word processing application other chapters in this book discuss the OpenOffice.org spreadsheet, graphics, and presentation software. But first, a word from our sponsor. Aside from its power and the absence of cost, a truly compelling reason for using OpenOffice.org Writer is its use of the new OpenDocument Format (ODF) standard for storing and exchanging documents Historically, all word processors used their own proprietary binary formats for storing documents, which made it a hassle when switching from one word processor to another or when simply trying to exchange documents with friends or coworkers who used a different word processor. The OpenDocument standard is...
You can start Writer from the command line by executing the oowriter command. More conveniently, a menu item for Writer is installed in the Applications C Office menu called OpenOffice.org Word Processor. To start Writer from the menus, select this menu item. The application starts, displaying an empty document, as shown in Figure 16-8. Starting Writer Starting Writer Writer provides excellent online help, as do all of the tools in the OpenOffice.org suite, so I won't bore you by walking you through each menu and entry that it contains. However, as a quick overview of the Writer interface, the callouts in Figure 16-8 highlight the following areas Menus The drop-down menus in Writer are organized much like the menus in Microsoft Word to provide a familiar user experience. Menu items with an arrow at their right edge lead to other, related submenus. Toolbars By default, Writer displays the Standard and Formatting toolbars, which provide one-click access to specific commands when you...
OpenOffice.org Writer offers a variety of useful features to help you create basic text documents as well as long and complex or multi-part Tables OpenOffice.org Writer also enables you to create or insert a table into a text document. This is a complete reference for your Writer.
If you are serious about using OpenOffice.org Writer for all of your documentation needs, the best site that I have seen on the Web for HOWTO information about using Writer is www.tutorialsforopenoffice .org. This site features great tutorials in PDF and OpenOffice.org formats, as well as links to a great selection of other sites with useful, hands-on information about using Writer. Check it out it's well worth your time After you become an OpenOffice.org wizard, you may want to create a tutorial of your own and contribute it to the site.
Sometimes, lock usage can be clearly divided into readers and writers. For example, consider a list that is both updated and searched. When the list is updated (written to), it is important that no other threads of execution concurrently write to or read from the list. Writing demands mutual exclusion. On the other hand, when the list is searched (read from), it is only important that nothing else write to the list. Multiple concurrent readers are safe so long as there are no writers. The task list's access patterns (discussed in Chapter 3, Process Management ) fit this description. Not surprisingly, the task list is protected by a reader-writer spin lock. When a data structure is neatly split into reader writer paths like this, it makes sense to use a locking mechanism that provides similar semantics. In this case, Linux provides reader-writer spin locks. Reader-writer spin locks provide separate reader and writer variants of the lock. One or more readers can concurrently hold the...
Click the OpenOffice Writer icon to launch the application. Click the taskbar icon the splash logo appears as the application loads. When the program is loaded, a new Writer application window containing an untitled document appears, as shown in Figure 12.2. A new OpenOffice Writer window. Because no document has been loaded by the user a new document Untitledl appears in the application window. The following are components that make up the OpenOffice Writer window The stylist window (which is titled Paragraph Styles) is helpful for long and complex documents requiring many different text styles, but we're not going to discuss it in this text. You can close it by clicking on the small button at its upper-right corner. If you want to experiment with it later on, you can display it once again by selecting Format, Stylist from inside OpenOffice Writer. You can also toggle the stylist off and on by pressing your F11 key.
(3) Writer TID 3076 is notified second that the buffer is full. (4) Writer TID 2051 is notified this time. Buffer is written out and this thread exits. Remaining writer thread does not exit until CTRL+C is entered. The output shows the writer threads alternating the task of displaying the output. At the end of the input sequence, CTRL+D causes the reader thread to signal the condition variable that termination is necessary. The thread to act upon the signal is the writer thread 2051 (2051 and 3076 are alternating). Writer thread 3076 (the thread ID passed to the single call to join) is unaware of the change, continues looping, and must be terminated with a CTRL+C. If we keep two writer threads and change the two pthread_cond_signai calls to pthread_cond_broadcast (lines 49 and 58), we obtain the output shown in Figure 11.13. Figure 11.13 A run of Program 11.6 with two writer threads, using broadcast notification.
The database writer (DBWn, also called DBWR) writes modified (dirty) blocks from the database buffer to disk. DBWR does this to clear out old dirty blocks to make room for new blocks in the cache. The DBA should note that this includes both committed and uncommitted data. There is normally one database writer process per database instance, but up to 10 DBWRs may be configured. Also, DBWR slave processes may also be used in some cases. These options are further described in Chapter 11.
One of the great things about Writer is that it can work with many file types. This capability allows you to create documents that can be used with various types of word-processing systems. Not only can you save new documents in various formats, but you can also read documents created in other word-processing programs. Here's a list of the document types you can use with OpenOffice.org Writer Microsoft Word 97 2000 XP (.doc) format yes, you can read and write Word documents using Writer The versatility of Writer is one of its primary features. You're not locked into a specific document format or style when you use Writer. Although the option is not available in the Save As dialog box, the OpenOffice. org Writer toolbar allows you to export any format of document to the PDF document format. You can create PDF documents from your Writer documents by pressing the Export Directly as PDF button. This generates a PDF document that is completely compatible with the Adobe Acrobat software...
Semaphores, like spin locks, also come in a reader-writer flavor. The situations where reader-writer semaphores are preferred over standard semaphores are the same as with reader-writer spin locks versus standard spin locks. Reader-writer semaphores are represented by the struct rw_semaphore type, which is declared in . Statically declared reader-writer semaphores are created via where name is the declared name of the new semaphore. Reader-writer semaphores that are created dynamically are initialized via All reader-writer semaphores are mutexes (that is, their usage count is one). Any number of readers can concurrently hold the read lock, so long as there are no writers. Conversely, only a sole writer (with no readers) can acquire the write variant of the lock. All reader-writer locks use uninterruptible sleep, so there is only one version of each down(). For example As with semaphores, implementations of down_read_tryiock() and down_write_tryiock() are provided. Each has one...
Opening OpenOffice Writer couldn't be easier click the Applications menu, select the Office group, and then click OpenOffice.org Word Processor, as shown in Figure 5-3. Figure 5-3. Selecting OpenOffice.org Word Processor opens Writer. Figure 5-3. Selecting OpenOffice.org Word Processor opens Writer. OpenOffice Writer 3.0 opens in a new window, as shown in Figure 5-4. Figure 5-4. OpenOffice Writer's user interface and a blank document. Figure 5-4. OpenOffice Writer's user interface and a blank document. Writer has the typical collection of drop-down menus along the top of the screen File, Edit, Insert, Format, Table, Tools, Window, and Help. And just below the menu bar is the first of two toolbars. Figure 5-5 shows the first toolbar with some descriptions of some of the buttons. As with many applications, hovering your mouse pointer over a button causes a small tooltip window to appear that can often help you figure out a button's function. You'll also see in Figure 5-5 that clicking...
In this section, I'm making some basic assumptions about your previous word processing experience. I assume that you know how to enter text, how to select text for formatting, and how to click menus and save files. If you're completely new to word processing (and possibly to using a computer), I recommend that you spend some time inside the OpenOffice Writer Help Center. Click the OpenOffice.org Help option. When the OpenOffice.org Help window opens (see Figure 5-9), click Instructions for Using OpenOffice.org Writer to learn about the basics of using this word processor. More than 100 basic skills are covered here, including using the mouse pointer to select and format text, indenting paragraphs, setting tabs, adding graphics, and more. I OpenOffice.org Writer OpenOffice.org Writer Help Working With OpenOffice.org Writer ODenOffke.org Writer Features Instructions for Usino OpenOffice.oro Writer Shortcut Kevs for OoenOffice.ora Writer Writer by clicking Figure 5-9. OpenOffice.org...
The first thing that you'll want to do when getting started with Writer is to enter some information about yourself into its User data fields. This is primarily useful because Writer will use this information in various places when filling out fields in documents that you create using the OpenOffice.org Wizards (as explained in the next section). Select the Tools O Options menu item to display the Options dialog's User Data form, as shown in Figure 16-12. Fill out the fields in this form and Click OK to return to Writer and your document. Writer's context-sensitive menu Writer's context-sensitive menu Writer's Online Help Writer's Online Help Writer's User Data form Writer's User Data form
Writer is a full-featured word processing application with the ability to save documents in a variety of standard and popular formats such as .odt, .doc, .html, and .pdf. Users of other word processing applications can open, read, print, and edit documents created in Writer without any concerns about compatibility. Users can also count on reliable technical support from a community of OpenOffice users, including many of the application developers as well as typical day-to-day users who are willing to help others with questions. One of the best sources of help and information on OpenOffice Writer (as well as Calc and Impress covered in Chapters 6 and 7) is the official OpenOffice web forum found at You can search the extensive database of existing questions and answers, and post your own questions. Figure 5-26 shows that each OpenOffice application has its own category, with Writer being at the top of the list followed by Calc, Impress, and more.
You don't really have to do any special setups to start using Writer. Even tasks such as printing should work right away provided you have set up a printer using the procedure described in Chapter 3. You may want to tinker with some settings, however, so that Writer works to your liking. For example, you might want to turn off AutoCorrect so that it doesn't suggest word completion, or you might want to hide some toolbars to get more workspace You can set up most of these options from the View and Tools menus, which are located on the Menu bar (refer to Figure 12-1). In particular, you perform many of the setup tasks from the dialog box (Figure 12-2) that appears when you choose ToolsOOptions. Set up many aspects of Writer from the Options dialog box. Set up many aspects of Writer from the Options dialog box.
The word processor is arguably the most popular element within any office suite. That said, you'll be happy to know that OpenOffice.org's Writer component doesn't skimp on features. It offers full text-editing and formatting functionality, along with powerful higher-level features such as mail merge. You'll find it on the Applications Office Word Processor menu within GNOME. Within KDE, click K menu Office Word Processor. In this chapter, we'll take a look at some ofWriter's most useful features. As with all of the components in the OpenOffice.org suite, describing the features within Writer could easily fill an entire book. You should do some exploring on your own by clicking around to discover new features, as well as make judicious use of the help system.
The OpenOffice.org word processor is a fast and easy-to-use application called Writer, and it's packed with every conceivable feature you could need. To run it, you can select Applications Office OpenOffice.org Word Processor or double-click any file that's associated with it, such as those with the extension .odt (the standard format used by OpenOffice.org and other free programs) or .doc. For example, Figure 12-1 shows the result of opening the file Welcome_to_Ubuntu.odt from within the example-content folder you just copied to your desktop. Figure 12-1. Editing a document in the Writer application Figure 12-1. Editing a document in the Writer application Although Writer can handle Microsoft Word files (like all parts of the OpenOffice.org suite), files with some complicated formatting elements do strange things if you move between Writer and Word. These problems are unpredictable and can range from strange page layouts to missing text. That said, different versions of...
Kurt Wall is a professional technical writer by trade and a historian by training. These days, Kurt works for TimeSys Corporation in Pittsburgh, Pennsylvania. His primary responsibility is managing TimeSys's Content Group. In addition to overseeing production of the technical and end-user documentation of TimeSys's embedded Linux operating system and development tools, he writes most of the documentation for TimeSys's embedded Linux products and all of the content available on the TimeSys Network. Kurt has written or co-written 15 books on Linux system administration and programming topics and contributes the occasional product review to LinuxPlanet. In his spare time, he has no spare time.
We work hard as a community to recognize the contributions of all sorts of individualsadvocates, artists, Web forum moderators, channel operators, community event organizers, writers, translators, people who file and triage bugs . . . whatever your particular interest or talent, we will find a way to integrate your contribution.
Jim Minatel is a freelance writer and editor with more than 13 years of publishing experience in mathematics, statistics, and computing. He has authored and co-authored several books about the Internet and World Wide Web in the early Netscape era, and most recently served as Editor in Chief for two magazines for networking professionals and IT managers. He holds undergraduate degrees in mathematics and physics, and an M.S. in mathematics.
ROB BASTIAANSEN is an independent consultant, trainer, and author. Rob has a strong focus on Linux and NetWare, clustering services, eDirectory, and ZENworks. He delivers advanced technical training for Novell in EMEA regarding these topics. Rob is also a technical writer he writes for several IT magazines in the Netherlands, where he lives. VMware is another area in which Rob works as a consultant and trainer. In 2004, Rob wrote and published his first book, Rob's Guide to Using VMware (Books4brains, 2004), and a second edition was published in 2005. In 2005, he published The NetWare Toolbox (Books4brains, 2005). He is a master-certified Novell instructor he has all the major Novell certifications, including Certified Linux Professional and he is LPI level 1 certified.
This license is part of the copyleft movement, which considers itself an alternative to traditional copyright laws.The GPL essentially allows anyone who develops code to ensure that the code remains open, meaning that GPL-licensed code can be taken and improved upon by anyone, as long as the improved code is given to the original writer and the software writing community. Consequently, a piece of code protected by the GPL will, by law, always remain accessible by anyone who wants to read or modify it.Without the GPL license, another person can take the code that you invent, and make it closed and proprietary. Associates, 2001). Although somewhat overly enthusiastic, it is a very helpful book in understanding the mindset of many open source code writers.
For good style in our command statements, we need it to be readable. For this reason it is sometimes better, for instance, to separate a command statement onto three separate lines instead of stringing, or piping, everything together on the same line of code in some cases, it is more desirable to create a long pipe. In some cases, it may be just too difficult to follow the pipe and understand what the expected result should be for a new script writer. And, again, it should have comments describing our thinking step by step. This way someone later will look at our code and say, Hey, now that's a groovy way to do that.
While we still have everything open to the Office menu, let's deal with what I consider to be another problem the order of the items in the menu. While it is natural enough to have the email client Evolution at the top of the menu, it doesn't make sense to have what is arguably the most commonly used OpenOffice.org module, Writer, way down there at the bottom of the menu. Remedying this situation is easy. Just click the OpenOffice.org Word Processor icon in the right pane of the menu editor window. Then click the up arrow on the right side of the window as many times as necessary until the Writer icon is right above the OpenOffice.org Base icon. Once you're done, your menu editor window should look something like mine in Figure 3-13.
There are a number of reasons to be interested in the writing of Linux device drivers. The rate at which new hardware becomes available (and obsolete ) alone guarantees that driver writers will be busy for the foreseeable future. Individuals may need to know about drivers in order to gain access to a particular device that is of interest to them. Hardware vendors, by making a Linux driver available for their products, can add the large and growing Linux user base to their potential markets. And the open source nature of the Linux system means that if the driver writer wishes, the source to a driver can be quickly disseminated to millions of users. This book will teach you how to write your own drivers and how to hack around in related parts of the kernel. We have taken a device-independent approach the programming techniques and interfaces are presented, whenever possible, without being tied to any specific device. Each driver is different as a driver writer, you will need to...
To download Fedora for installation from a DVD CD-ROM drive, you download the CD or DVD ISO images. These are very large files that reside in the iso directory on the download site and have the extension .iso. Once they are downloaded, you burn them to a disk using your CD or DVD writer and burner software, like the GNOME Nautilus file manager or K3b.
So what happens if, let's say, you are running OpenOffice.org Writer in one workspace and the GIMP in another, but suddenly think that it would be handy to have them both running in the same workspace Do you quit the GIMP and start it up again in the other desktop Fortunately, things are much simpler than that, and there are actually two ways to get the job done.
On the office side of the business, Jim relies entirely on Fedora Linux systems. He uses OpenOffice.org Writer for documents, GIMP and Inkscape for logos and other artwork, and GnuCash for accounting. For Web browsing, Firefox is used. So far, there has been no need to purchase any commercial software.
Of course, no matter what browser or e-mail client you are using, you need to follow good security practices (such as not opening attachments or downloading files you don't trust). Also, as open source browsers and e-mail clients, such as those from Mozilla.org, become more popular, the number of possible machines to infect through those applications will make it more tempting to virus writers. (At the moment, most viruses and worms are created specifically to attack Microsoft software.)
The bottom line of any computer system is storing, retrieving, manipulating, and saving information. As a writer and computer systems administrator, I'm always amazed when friends who are generally computer savvy say to me, Your laptop is so slow. Why don't you upgrade Frankly, if I could type faster than my primary laptop's 1.4 GHz Pentium processor could handle, I'd be posing for Ripley's Believe It or Not ads or touring with the circus instead of writing books. On the other hand, if it took five minutes for me to save a chapter of whatever I'm working on or if I could never find the space to save a modified file without deleting something else, I'd drop-kick my current laptop into the river in a heartbeat and buy the newest, brightest, shiniest Linux-capable laptop available today. For what I do, being able to reliably and quickly read and write data is far more important than blazing CPU speed.
A module writer must also specify the -O flag to the compiler, because many functions are declared as inline in the header files. gcc doesn't expand inline functions unless optimization is enabled, but it can accept both the -g and -O options, allowing you to debug code that uses inline functions. Because the kernel makes extensive use of inline functions, it is important that they be expanded properly.
For many people, one of the most important pieces of computer software is a word processor. Although I am using one to write this book (OpenOffice.org Writer), it's not something I use often. The last time I used a word processor was four years ago when I wrote my previous book. A text editor, on the other hand, is an indispensable tool. I use one for writing e-mail, Usenet articles, shell scripts, PostScript programs, web pages, and more.
With GNOME, burning data to a DVD or CD is a simple matter of dragging files to an open blank CD or DVD and clicking the Write To Disk button. When you insert a blank DVD CD, a window will open labeled CD DVD Creator. To burn files, just drag them to that window. All Read Write disks, even if they are not blank, are also recognized as writable disks and opened up in a DVD CD Creator window. Click Write To Disk when ready to burn a DVD CD. A dialog will open as shown in Figure 3-9. You can specify write speed, the DVD CD writer to use (if you have more than one), and the disk label.
Many excellent tools are available for writing ISO files to CD DVD media. Some Linux distributions use the cdrecord command Ubuntu uses the cdrdao command. Excellent GUI front ends to these commands are available through the Nautilus file browser and the K3b writer. Microsoft based CD DVD write applications can burn ISO files to CD DVD media equally well.
Now click the rectangle labeled 3 and open the OpenOffice.org Writer by clicking the Main menu icon (the red hat or Fedora logo), clicking Office from the pop-up menu, and then clicking Word Processor from the submenu. With Writer in workspace 3 and Firefox in workspace 2, you can click the rectangles in the Pager to switch back and forth between the workspaces. GNOME calls this tool the Workspace Switcher.
Basically, there are two ways to obtain the correct values either the user specifies them explicitly or the driver autodetects them. Although autodetection is undoubtedly the best approach to driver configuration, user configuration is much easier to implement. A suitable trade-off for a driver writer is to implement automatic configuration whenever possible, while allowing user configuration as an option to override autodetection. An additional advantage of this approach to configuration is that the initial development can be done without autodetection, by specifying the parameters at load time, and autodetection can be implemented later. If the configuration variables are used only within the driver (they are not published in the kernel's symbol table), the driver writer can make life a little easier for the user by leaving off the prefix on the variable names (in this case, skull_). Prefixes usually mean little to users except extra typing.
You should avoid Windows-specific hardware for two reasons. The first is that the manufacturers do not generally make the resources available to write a Linux driver. Generally, the hardware and software interface to the device is proprietary, and documentation is not available without a nondisclosure agreement, if it is available at all. This precludes it being used for free software, since free software writers disclose the source code of their programs. The second reason is that when devices like these have had their embedded processors removed, the operating system must perform the work of the embedded processors, often at real-time priority, and thus the CPU is not available to run your programs while it is driving these devices. Since the typical Windows user does not multi-process as intensively as a Linux user, the manufacturers hope that the Windows user simply won't notice the burden this hardware places on their CPU. However, any multi-processing operating system, even...
Many distributions of Linux include the entire OpenOffice.org suite of desktop applications. Some include the StarOffice suite in addition to or in lieu of OpenOffice.org. Because of its size, the entire OpenOffice.org suite is usually not included on live CD versions of Linux. However, with an Internet connection, you can usually download and install prepackaged versions of the OpenOffice.org suite. For example, in Fedora, you can install the openoffice.org-calc, openoffice.org-draw, openof-fice.org-impress, openoffice.org-writer, and openoffice.org-math packages to get most of the suite. Writer A word-processing application that can work with documents in file formats from Microsoft Word, StarOffice, and several others. Writer also has a full set of features for using templates, working with fonts, navigating your documents (including images and effects), and generating tables of contents. Unlike other applications that were created to work with Microsoft document and data formats,...
As with software development, the community contributes towards the development and enhancement of this desktop course. As Ubuntu experts, the community defines the scope and structure of the training by identifying requirements from the users' perspective they also assist the Canonical and third-party content writers in developing content and reviewing it. More information on the Ubuntu Training community effort can be found at http wiki.ubuntu.com Training.
. Writer This word processing program enables you to compose, format, and organize text documents. If you are accustomed to using Microsoft Word, the functionality of OpenOffice.org Writer will be familiar to you. You will learn how to get up and running with Writer later on in this chapter. Math This math formula editor enables you to write mathematical formulas with a number of math fonts and symbols for inclusion in a word processing document. Such symbols are highly specialized and not easily included in the basic functionality of a word processor. This is of interest primarily to math and science writers, but Math can be useful to anyone who needs to include a complex formula in text.
One of the significant benefits of using Writer is the ability you have to easily apply formatting and styles to extremely complex documents. Depending on the types of documents you work with, you might want to consider creating your own styles beyond the 20 included by default. You can access styles through either the Style drop-down box in the toolbar or the Styles and Formatting window shown in Figure 6.5. If you cannot see the window, press the F11 key to display it. FIGURE 6.5 Writer's quick and easy-to-use Styles and Formatting tool. FIGURE 6.6 Writer's powerful Style Catalog gives you control over every aspect of styling. FIGURE 6.6 Writer's powerful Style Catalog gives you control over every aspect of styling.
Sun's Star Office has very good support for Microsoft Office files. It offers equivalent programs for word processing (Writer), spreadsheets (Calc), presentations (Impress), graphics (Draw), email (Mail), calendaring (Schedule), and a database (Base). It also has an integrated Web browser. While it is not as feature-rich as Microsoft Office, it offers all its major functions such as fonts, headers, footers, and template style sheets. Star Office isn't for everyone, though. Probably the biggest drawbacks are its size and speed. Star Office requires 160MB of disk space and at least 32MB of RAM, although 64MB is required to get decent performance. It also takes a long time to load, even on a fast system. Low-end machines that are often used for Linux boxes are definitely out of the question.
You begin the actual development process by typing your program code into a text editor. Which text editor doesn't matter very much, and there are dozens from which to choose. (I'll recommend a very good one in the next chapter.) The only important thing to keep in mind is that word processors such as Microsoft Word and OpenOffice Writer embed a lot of extra binary data in their document files, above and beyond the text that you type. This binary data controls things such as line spacing, fonts and font size, page headers and footers, and many other things that your assembler has no need for and no clue about. Assemblers are not always good at ignoring such data, which may cause errors at assembly time.
Mmap_sem This is a long-lived lock that protects the VMA list for readers and writers. Because users of this lock require it for a long time and may need to sleep, a spinlock is inappropriate. A reader of the list takes this semaphore with down_read(). If they need to write, it is taken with down_write(), and the page_table_lock spinlock is later acquired while the VMA linked lists are being updated.
Linux is distributed across the Internet through the use of ISOs that are waiting to be written to CDs or DVDs. Therefore, learning how to burn discs is essential if you have to download and install a Linux distribution. Not only that, but you are likely to want to use CDs and, more commonly, DVDs to back up your music, family pictures, or other important files. With DVD writers being so cheap, the format is now pervasive, and more and more people use cheap DVDs as way of archiving simply due to the larger storage size available. Of course, you can use blank CD media, but they don't have anywhere near the capacity offered by DVDs albeit being slightly cheaper. Today's high-resolution digital cameras can occupy upward of 3MB per shot, and music files can be anything from 1MB to 10MB+ in size. These file sizes make DVD the obvious choice, but there are still occasions when you need to write to a CD. You can use CDs and DVDs to Linux audio clients and programs support the creation and...
The Programs menu was built for SUSE (indicated by the Novell icon attached to it) and is identical to the default Kicker menu in KDE, but there is a separate menu for quick access to System tools, including YaST, the file finder, and the logout button. The left side default applications include the Epiphany web browser, the Evolution groupware personal information manager tool, and OpenOffice.org Writer, along with SUSEWatcher and SUSEPIugger. On the right, in addition to the clock, is the volume control and the list of all open applications.
Although use of the special filesystem is not widespread as we write this, the new features offer a few advantages to the device driver writer. Therefore, our version of scull exploits devfs if it is being used in the target system. The module uses kernel configuration information at compile time to know whether particular features have been enabled, and in this case we depend on CONFIG_DEVFS_FS being defined or not.
A number of factors drove the changes in the file_operations methods. The longstanding 2 GB file-size limit caused problems even in the Linux 2.0 days. As a result, the 2.1 development series started using the loff_t type, a 64-bit value, to represent file positions and lengths. Large file support was not completely integrated until version 2.4 of the kernel, but much of the groundwork was done earlier and had to be accommodated by driver writers. Two other incompatibilities are related to the file_operations structure. One is that the flush method was added during the 2.1 development cycle. Driver writers almost never need to worry about this method, but its presence in the middle of the structure can still create problems. The best way to avoid dealing with the flush method is to use the tagged initialization syntax, as we did in all the sample source files.
The first document and graphics tools for Linux were mostly built on older, text-based tools. Despite their age, many of the older publishing tools such as Groff and LaTeX are still used by people in the technical community. With these old-school text processors you can ignore document appearance while writing. Plain-text macros instruct post-processors how to lay out a document for printing after writing is done. With word processors (such as OpenOffice.org Word and StarOffice Writer), you mark up text and see the basic layout of the document as you write.
You can create the documents in any text editor, using tags that are similar in appearance to HTML tags (with beginning and end tags appearing between less-than and greater-than signs). There are also word processing programs that allow you to create DocBook markup. You can export documents from OpenOffice.org Writer to DocBook format, for example.
Spinlocks are a simple mechanism by which only one process at a time can acquire the lock, for whatever purpose, but in some cases this can be overrestrictive. Frequently, it is permissible for more than one process to acquire the same lock simultaneously, if all of such processes are only reading the data controlled by the lock, and none of them is going to write to it. Such a mechanism is known as a read-write lock. Processes can take out either a read lock (excluding writing) or a write lock (mutually exclusive) on such a lock, so there can be multiple readers at the same time, but only one writer with no readers.
Read-write locks are implemented as a 25-bit counter with the high bit being the writer bit. When this is clear, it means that a write lock is held. When set, it means that no writer is holding the lock. The low-order 24 bits count the number of readers. A 0 value here means there are no readers. Every time a read lock is taken out, the value of the lock field is decremented. This has the side-effect of clearing the write bit as well. Figure 5.33, from , shows two macros used when setting and testing such locks.
The first function, which takes out a read lock, is shown in Figure 5.35, from . The code in this function is concerned mainly with debugging the real work is done by a subsidiary macro. If a writer is holding the lock, it busy waits. pointer to the lock and the name of a 'helper' subroutine to be called if a writer is holding the lock.
25-36 this macro deals with the case when the lock is passed by reference. The second parameter is a string representing the name of the 'helper' routine, which is executed if a writer is holding the lock. 27 if the result was negative, the sign bit was set. The value must have been 0 beforehand, implying that a writer is holding the lock, so this causes a jump to label 2 at line 33. 29 this block of code is assembled into a section named .subsection 1. This code is (one hopes) seldom executed, only when a writer is holding the lock, so it is compiled into a different section to avoid filling the cache with unused code. 33 control transfers here if a writer was holding the lock. The helper routine is called, as specified by the caller. 38-52 this macro deals with the case when the compiler was able to determine that the rw parameter was a constant at compile time. The second parameter is a string representing the name of the 'helper' routine, which is executed if a writer is holding...
Nautilus features built-in DVD CD-burning support with the nautilus-cd-burner package for both files, ISO images, and DVD Video. Burning a data DVD CD is a simple matter of placing a blank DVD CD in the appropriate drive. Nautilus automatically recognizes it as a blank disc and allows you to write to it. All read write discs, even if they are not blank, are also recognized as writable discs and opened in a DVD CD writer window. To burn a disc, drag the files you want to copy to the blank disc window and then click Write To Disc. A dialog will open with buttons to set options such as the write speed and disc label. After writing the disc, a dialog shows buttons to Eject, Burn Again, or Close. Keep in mind that the newly written disc is not mounted. You can eject it at any time.
This routine is called, with a pointer to the lock field in EAX, if either of the macros described in Section 5.7.4 failed to acquire a write lock (because a writer, or readers, are holding it). 257 this routine is called, with a pointer to the lock field in EAX, if either of the macros in Section 5.7.3 failed to acquire a read lock because a writer was holding it. 260 this comparison instruction works by doing a dummy subtraction of 1 from the lock field. If the lock field was 0 beforehand (a writer was holding it), this will set the sign bit otherwise (there is no writer) the sign bit is not set. 261 if the comparison sets the sign bit, there is a writer holding the lock so we jump back to label 1 and spin on the lock until that writer exits. 263 there should be no writer at this stage. The lock is decremented as an atomic operation. 264 just in case a writer got in between lines 261 and 263, the sign bit is checked again. If it is set, we try again.
The function shown in Figure 6.21, from , attempts to acquire a read-write semaphore for reading. The calling process will be put to sleep only if a writer is holding the semaphore. 103 if the most significant bit is set, the semaphore is held by a writer, and control jumps on to label 2 at line 109. As the next block of code is compiled into a different subsection, if the most significant bit is clear, control falls through to the end of the assembler code and the function terminates, with the caller holding the semaphore. The function shown in Figure 6.22, from , attempts to acquire a read-write semaphore for writing. The calling process will be put to sleep if any other process (reader or writer) is currently holding the semaphore. the local tmp variable is initialised to 1 - 00010000, which is FFFF 0001, This indicates one active lock and one active writer. for the semaphore to be granted for writing, count must have been 0 beforehand, (i.e. no readers and no writers). The local...
When either of the functions described in Sections 188.8.131.52 or 184.108.40.206 finds that the semaphore is now free, it calls rwsem_wake() to check if a waiting process needs to be woken. This function is shown in Figure 6.29, from lib rwsem.c. The state of the count field on entry to this function is that the number of active holders has been decremented (in both the read case and the write case), and, in the writer case, that the negative value representing the active writer has also been removed. 59-60 if the first process waiting is a reader, then a jump is made to line 71 to handle readers. Otherwise, lines 62-64 are used to handle a single writer. 62 one waiting writer is removed from the wait queue, using the function from Section 4.3.3. 71 -97 the semaphore is granted to all waiting readers clustered together at the head of the queue. This stops when the first waiting writer is encountered. 99 control either falls through to here from line 97, jumps to here from line 65, when finished...
OOo also provides a separate QuickStarter program that places an OOo icon in both the KDE and GNOME taskbars. Install ooqstart from YaST and then right-click the icon when you want to load a OOo component. Double-clicking the QuickStarter icon brings up a new Writer document by default. This is configurable. Choose Configure OpenOffice.org QuickStarter from the QuickStarter menu.
After you have played around with Ubuntu for a while, you may have made some changes to the desktop environment. Maybe you added some icons or changed the background. Quite possibly, you used Open Office and created a document or spreadsheet. Unfortunately, you cannot save your changes or your work to your computer's hard drive in the live environment. The purpose of the Live CD is to allow you to get a feel for GNU Linux and see if it is compatible with your computer before installing the software. If you sat down to a live session and completed the Great American Novel on Writer, or knocked out your company's quarterly projections on Calc, not to fear. You can still save this work on a USB drive or some other removable media. The desktop changes, however, will not stay once you shut down your live session.
User-Mode Linux also has some significant limitations as of this writing, most of which will likely be addressed soon. The virtual processor currently works in a uniprocessor mode only the port runs on SMP systems without a problem, but it can only emulate a uniprocessor host. The biggest problem for driver writers, though, is that the user-mode kernel has no access to the host system's hardware. Thus, while it can be useful for debugging most of the sample drivers in this book, User-Mode Linux is not yet useful for debugging drivers that have to deal with real hardware. Finally, User-Mode Linux only runs on the IA-32 architecture.
The net device structure, defined in file linux include netdevice.h, is the data structure that defines an instance of a network interface. It tracks the state information of all the network interface devices attached to the TCP IP stack. The structure might seem longer and more complex than is necessary, but it contains fields for implementing devices that have been added after the more generic network interfaces were originally defined. In our description of the net_device structure, the fields that are of most interest to network interface driver writers contain explanations. We also include explanations of the things needed to connect the network interface driver to the TCP IP stack. In general, we concern ourselves only with the public part of the driver's data structure, but some key fields in the private part of the driver's data structure are important for PCI devices. This is because they must be initialized with a pointer to the PCI card's configuration space, and this...
After all the initialization of the net device structure and the associated private data structure is complete, the driver can be registered as a networking device. Network device registration consists of putting the driver's net device structure on a linked list. The files linux net core dev. c and linux net net_init. c provide utility functions to do the registration and perform other tasks. Most of the functions involved in network device registration use the name field in the net_device structure. This is why driver writers should use the dev_alloc_name function to ensure that the name field is formatted properly. The list of net devices is protected by the netlink mutex locking and unlocking functions, rtnl_lock and rtnl_unlock. The list of devices should not be manipulated without locking because if the locks are not used, it is possible for the device list to become corrupted or two devices that try to register in parallel to be assigned the same name. The device interface...
OpenOffice.org Writer You run the spadmin program to administer fonts and printers. (You may need to change into the directory in which this program resides to run it or it will get confused.) Click the Fonts button to enter the font manager (as shown in Figure 7.6). You can then add TrueType or PostScript fonts by clicking Add and selecting the fonts you want to add in the resulting file selector. Unfortunately, OpenOffice.org's font installer tends to be very finicky sometimes it won't install a font, or will appear to install a font but not make it available, or display a similarly-named X font instead.
Linux Documentation Project (www.linuxdoc.org LDP LDP-Author-Guide) Gnome Documentation Project KDE Documentation Project (www.kde.org documentation) Open Source Writers Group (http www.oswg.org ) FreeBSD Documentation Project (www.freebsd.org docproj) If you wanted to contribute to any of the above documentation projects, refer to the Web sites for each organization. In all cases, they publish writers' guides or style guides that describe the DocBook tags that they support for their writing efforts.
For most current-generation Beowulf nodes, the Logical Link Control sublayer incorporates an interface to the PCI bus. This element of the Ethernet controller provides all logical control required to accept commands from the host processor and to provide direct memory access to the node main memory for rapid data transfers between memory and the network. Usually included is some form of FIFO buffering within the Data Link Layer to hold one or more incoming or outgoing messages in the node. The Logical Link Control sublayer presents variable-length byte sequences to the Media Access Control sublayer and accepts data byte sequences from it. The exact form and operation of the Logical Link Control sublayer is not standardized, and manufacturer differences are a source of headaches for device driver writers.
With LaTeX-2e it is possible to quickly produce high-quality output through a laser printer using a text editor such as vi or emacs. In fact, many professional writers, self-publishers, and educators swear by LaTeX rather than more common and widely understood WYSIWYG word processors, largely because LaTeX makes the production of high-quality output so easy.
Toggle various parts Select the appropriate item such as Ruler, Status Bar, or Toolbars of Writer window from the View menu and toggle that item on or off. on or off Show nonprintable Choose ToolsOOptions. Then choose Text DocumentOFormatting characters, such as Aids and turn on the check box of characters you want Writer to paragraph marks, display. tabs, and so on
The cdrecord utility is a command line utility for recording files onto writable CDs using an appropriate CD-Writer drive (CD-R or CD RW). It is installed by default in Red Hat Linux 9, and its web site can be found at If you find all this command line stuff too daunting, you could use the GnomeToaster application. GnomeToaster is a graphical CD recording utility written for the GNOME environment. You can start this application by selecting Main Menu System Tools More System Tools CD Writer, or by typing gtoaster at the command line
Not all device classes can be attached to all bus systems. For example, it is possible to connect hard disks and CD writers but not graphic cards to an SCSI interface. However, the latter can be housed in PCI slots. In contrast, hard disks must be attached to a PCI bus via another interface (typically IDE). Communication with bus-attached devices need not be performed in kernel space in the form of a device driver but in some cases may also be implemented from userspace. Prime examples are SCSI writers that are typically addressed by the cdrecord tool. This tool generates the required SCSI commands, sends them to the corresponding device via the SCSI bus with the help of the kernel, and processes the information and responses generated and returned by the device.
In LaTeX, paragraph formatting (indentation, skipping space between paragraphs, and so on) is handled automatically. The only task left to the writer is to indicate when a new paragraph should begin. You do this by inserting a blank line in the LaTeX source file using your text editor's Enter key. Sometimes it is the writer's intent to insert a line break. You can think of a line break as being like pressing the Enter key in the middle of a paragraph in a plain text file the cursor moves to a new line without beginning a new paragraph, indenting, or leaving empty vertical spaces after the previous line.
In Writer, page styles control the page layout, and each page can have its own style. The usual approach is to define three page styles First Page, Left Page, and Right Page. Define the First Page with whatever applies to the first page, such as a special header and no page number. The Left Page is the style for the even numbered pages and the Right Page style is for odd numbered pages. For each page style, you can also define the page style that applies to the following page. The idea is to define Left Page as the next page style for First Page and Right Page as the style of the page that follows the Left Page style. That way, the page styles are correct for all the pages as long as you start with the First Page style. You may also want to define a Landscape page style so you can use it for pages that have to be in landscape orientation. If you are familiar with Microsoft Word, you know that the page setup paper size, orientation, margins, and so on applies to all pages in the...
With Ubuntu, enhanced functionality has been included in the default file browser Nautilus. Under the Places menu item is a CD DVD Creator selection. To use it, insert a blank CD or DVD into your CD-R DVD-R drive. You will need to have two Nautilus windows open one showing the files you want to save to the CD, and a second one that is opened to the burn location. Click on the Write to Disc button as shown in Figure 10.1 to bring up the Write dialog at the next dialog box, choose what format you want to write the disc to. Nautilus CD DVD Creator supports writing to a disc image file, commonly known as ISO. You can also give your new disc a label and tell Nautilus what speed you want to write the disc at. Finally click the Write button to start the burning processit is that simple Nautilus also allows you to quickly write an ISO file directly to a disc. Simply right click on the ISO file that you want to burn to a disc, and select Write to Disc. You will be asked to confirm the CD...
Writer includes a drawing toolbar with tools that you can use to draw in the r o Writer also comes with a gallery of predefined graphics. To view the Gallery (shown in Figure 1-10), choose ToolsOGallery or click the Gallery icon (the second- from right icon on the function bar). Select from the themes along the left side of the Gallery. If you see a graphic you want to use, drag and drop it from the Gallery to the location in the document where you want to insert it. Click the Gallery icon again to hide the Gallery. Table 1-6 summarizes how you can work in Writer to perform some common tasks involving graphics. Table 1-6 summarizes how you can work in Writer to perform some common tasks involving graphics.
StarOffice Writer The Writer is the name for the word processor function in StarOffice. You have many of the commonly known tools in a left column tool bar on the side of the document window. Spell checking can be automatic or manual you get to choose. It performs many automated tasks, such as auto-correcting text as you write or simply pointing out text that you need to correct.
When you launch Writer, you are put into a new document automatically, so there is no need to do anything other than simply begin typing. If you'd like help building your document, Writer provides a selection of AutoPilots for commonly used documents such as fax cover pages, sales contracts, and school papers. Tip To set a style for your document, use the Paragraph Stylist. It is turned on automatically when you launch Writer. Turn it on or off by selecting Stylist from the Format menu.
Several CD writer programs that can be used for CD music and MP3 writing (burners and rippers) are available from www.kde-apps.org. These include K3b, CD-Rchive, and KAudioCreator (CD ripper). For GNOME, you can use CD-REC and the Nautilus CD burner, which is integrated into the Nautilus file manager, the default file manager for the GNOME desktop. All use mkisofs, cdrecord, and cdda2wav CD writing programs, which are installed as part of the Red Hat distribution. GNOME also features two CD audio rippers installed with Red Hat Fedora, Grip, and Sound Juicer.
If you're going to present information that's already in a Writer document (see Chapter 1 of this minibook), you can use the outline of that Writer document to start a presentation. The Writer document does have to follow one rule it must use the heading styles (Heading 1, Heading 2, and so on) for the major sections in the document. To create a presentation from the outline of a Writer document that uses the heading styles, open the document in Writer and choose SendOOutline to Presentation from the Writer menu. An Impress window opens with a new presentation with slides based on the headings in the Writer document. Each Heading 1 style becomes a new slide and the Heading 2 and Heading 3 styles appear as bulleted text in the slides.
The K Desktop mail client, KMail, provides a full-featured GUI interface for composing, sending, and receiving mail messages. KMail is now part of the KDE Personal Information Management suite, KDE-PIM, which also includes an address book (KAddressBook), an organizer and scheduler (KOrganizer), and a note writer (KNotes). All these components are also directly integrated on the desktop into Kontact. To start up KMail, you start the Kontact application. The KMail window displays three panes for folders, headers, and messages. The upper-left pane displays your mail folders. You have an inbox folder for received mail, an outbox folder for mail you have composed but have not sent yet, and a sent-mail folder for messages you have previously sent. You can create your own mail folders and save selected messages in them, if you wish. The top-right pane displays mail headers for the currently selected mail folder. To display a message, click its header. The message is then displayed in the...
When you install the Ubuntu operating system (version 8.10 for this book) on your computer, a large collection of free applications is installed, including OpenOffice Writer, Calc, and Impress. The applications are ready to use no installation required. But the OpenOffice suite has one drawback the version of OpenOffice installed with the Ubuntu operating system is version 2.4, and the most current version of OpenOffice is version 3.0 (as this chapter is being written). This chapter uses the version 3.0 user interface for all OpenOffice applications, but there is nothing stopping you from following along with this chapter's examples (as well as those in Chapter 6 and Chapter 7) using version 2.4. There might be slight differences in naming conventions for menus, tool buttons, and windows that open, but many of the actions required while using Writer version 2.4 are similar if not identical to those in version 3.0. That said, I'll provide a web site that contains instructions for...
In short, normal driver writers have two choices. First, do you need a schedulable entity to perform your deferred work fundamentally, do you need to sleep for any reason Then work queues are your only option. Otherwise, tasklets are preferred. Only if scalability becomes a concern do you investigate softirqs.
Draw is a separate drawing program in the OpenOffice.org office application suite, but you can also access many of Draw's drawing tools from other OpenOffice.org applications, such as Writer and Impress. When you use Draw to prepare drawings, you save the drawing in a file. You can later insert the drawing as a Draw object into other OpenOffice.org documents, such as a Writer document or an Impress presentation. The nice part about inserting a Draw object into a Writer or Impress document is that you can always doubleclick and edit the drawing directly, even while it's in the Writer or Impress document.
The selling point in favor of TCP IP for most application writers is that the communication channel is transparently reliable and that data is delivered in the proper sequence. After the connection has been established, your application can read and write to the socket without worrying about any of the following problems
A conglomerate kernel containing all drivers in this manner presents several problems. First of all, it requires the system administrator to rebuild the kernel in order to selectively include device drivers, as we saw in the previous section. Also, this mechanism lends itself to sloppy programming on the part of the driver writers there's nothing stopping a programmer from writing code that is not completely modular code which, for example, directly accesses data private to other parts of the kernel. The cooperative nature of the Linux kernel development compounds this problem, and not all parts of the code are as neatly contained as they should be. This can make it more difficult to maintain and debug the code.
If you're like me, you can't type a paragraph without a misspelled word creeping into a sentence or two. For me, it's not a reflection of my spelling abilities I type so fast that I tend to make a lot of mistakes. So it's nice to see that Writer alerts me to my misspelled words by placing a wavy line underneath the problem words, as shown in Figure 5-10. Writer makes it so easy to fix misspelled words, too simply right-click a misspelled word and select the correctly spelled word, as shown in Figure 5-11. Only a single occurrence of that word is fixed at a time in your document in Figure 5-10, for example, the incorrectly spelled word mispelled appears twice and fixing one of them does not correct the other occurrence.
No doubt you've heard media reports regarding the genesis of Linux from a bunch of hackers, the profits of the major distributions, high-profile corporate relationships with Linux, and Linux as a Wall Street darling. It is well known that coders around the world are contributing to the Linux code base. Rarely mentioned, however, are the many dedicated writers working in the public domain to make sure that Linux is as well understood as it is stable. Most of the people who contribute to the LDP do so on their own time, providing information learned from their own experiences. In most cases, the people who write for the LDP provide their names and email addresses so you can contact them with questions that remain unanswered. These writers are partially responsible for the widespread growth of Linux, because they make it understandable to individuals through documentation efforts not usually seen with commercial software.
Most of the documentation in usr doc and elsewhere on a Linux system is part of an organized approach to system documentation. The Linux Documentation Project, or LDP, is a loosely knit team of writers, proofreaders, and editors who work together to create the definitive set of documentation for Linux. The main web site can be found at http www.linuxdoc.org and at many mirror sites throughout the world.
Writer can save documents in many different formats. Figure 5-12. Writer can save documents in many different formats. By default, Writer saves your documents using the .odt file type. Scrolling down that list, you'll also see that you can save in .doc format (for compatibility with Microsoft Word) as well as many other formats, including .html (for use as web pages). But you won't find another popular file format, .pdf, in that list. Instead of saving a document as a .pdf file, you must instead export the document as a separate file. To do this, click the PDF button indicated in Figure 5-13 provide a name and location to save the file and then click the Save button. The current document is exported and saved with the .pdf extension.
Architecture-dependent value defined in . Current Linux versions define HZ to be 100 for most platforms, but some platforms use 1024, and the IA-64 simulator uses 20. Despite what your preferred platform uses, no driver writer should count on any specific value of HZ. Every time a timer interrupt occurs, the value of the variable jiffies is incremented. jiffies is initialized to 0 when the system boots, and is thus the number of clock ticks since the computer was turned on. It is declared in as unsigned long volatile, and will possibly overflow after a long time of continuous system operation (but no platform features jiffy overflow in less than 16 months of uptime). Much effort has gone into ensuring that the kernel operates properly when jiffies overflows. Driver writers do not normally have to worry about jiffies overflows, but it is good to be aware of the possibility.
To make sure Linux can recognize your CD writer, type the following command After you have added your CD writer as a SCSI device, it may no longer be available to the CD players described in this chapter. By default, those players play the dev cdrom device, which in this case points to an IDE drive. To fix that, type the following as root user
Compared to floppy drives and some removable drives, CD-RW drives and their cousins, DVD+RW -RW drives, can store large amounts of data and are useful for a home or small business. Once very expensive, CD writers and media are at commodity prices today, although automated CD changing machines, necessary for automatically backing up large amounts of data, are still quite costly. A benefit of CD and DVD storage over tape devices is that the archived uncompressed file system can be mounted and its files accessed randomly just like a hard drive (you do this when you create a data CD, refer to Chapter 10, Multimedia Applications ), making the recovery of individual files easier.